The work reported in this paper was carried out as part of a project funded by the Tyndall Centre for Climate Change Research. The project - “The Hydrogen Energy Economy: its long term role in greenhouse gas reduction” (Dutton et al., 2004) – was a collaboration between the Energy Research Unit at the CCLRC Rutherford Appleton Laboratory, the Science and Technology Policy Research Unit (SPRU) at the University of Sussex and the Institute for Transport Studies (ITS) at the University of Leeds. The project studied the potential contribution and viability of the hydrogen energy economy towards reducing UK carbon dioxide emissions in the time horizon to 2050. This paper reports on the development and application of a quantitative model of the UK transport sector as part of this work. This model was developed to explore the degree to which hydrogen powered vehicles could play a major role in the UK transport sector and the potential impact on energy consumption under a range of future scenarios to 2050. The model incorporated the four main motorised modes and estimates the amounts of different types of fuel consumed by the UK transport industry up to 2050. Scenarios were used to inform the development of inputs to the model and therefore the model was able to shed light on the practicality of the scenarios, and the potential impact of hydrogen in each.